s1ce - Voting will revert because of incorrect use of getPriorVotes

[sherlock-admin]

s1ce

high

Voting will revert because of incorrect use of getPriorVotes

Summary

getPriorVotes is used incorrectly which will cause all voting actions to revert

Vulnerability Detail

In castVoteInternal, there is the following line of code:

uint256 currentVotes = gohm.getPriorVotes(voter, block.number);

However, if we look at the implementation of gohm on mainnet (https://etherscan.io/token/0x0ab87046fBb341D058F17CBC4c1133F25a20a52f#code):

The first line of getPriorVotes is:

require(blockNumber < block.number, "gOHM::getPriorVotes: not yet determined");

So the function getPriorVotes is not callable with the current block number, so castVoteInternal will always revert. This means users will be unable to vote.

Impact

Users cannot vote for proposals; their transactions will revert.

Code Snippet

https://github.com/sherlock-audit/2024-01-olympus-on-chain-governance/blob/main/bophades/src/external/governance/GovernorBravoDelegate.sol#L446

Tool used

Manual Review

Recommendation

Use block.number - 1 instead of block.number

Duplicate of #37